Linking three fans via a single motherboard header
Linking three fans via a single motherboard header
It’s acceptable to link three X SP120MM Corsair fans using a single motherboard header with a fan splitter cable. Your setup allows for it on a compact Z270 ROG Strix G, especially since you only have two fan headers and plan to add more later. Connecting the pump to the CPU header is fine per the manual, but consider routing the CPU fans through the pump’s built-in splitters if possible. The two radiator fans on the CPU and CPU opt header can also be connected together for balanced cooling.
I think most motherboards allocate power to the CPU fan and pump headers equally, so the best choice might be connecting the pump to the pump header and using rad fans for the CPU. This lets you keep your CPU-OPT open while freeing the chassis fan header for case fans.
I have two Rad fans and need to use CPU opt. Using them limits my header count. Adding an exhaust would affect performance. The cooler should still function if I keep the fan splitter setup, but connecting to the CPU block is necessary for proper operation.
I recall working through this in another discussion where it was explained that a PWM fan hub is necessary for 4-pin fans to function properly. The problem isn't the power supply, but how the fans are controlled. If you need to combine or split the header, a hub is required and will draw power from a SATA connector at 12V. Cheap 2-pin fans tend to be noisy and can work on the same header, but it's better to connect them through a series of SATA/Molex power sources rather than relying on a single shared header.
The components included with the case list 12V DC 0.30A, which should protect your motherboard and fans from damage. You're right, that should keep things safe. Thanks!
I’m setting up a 1-3 fan splitter using SP120 RGB fans with three-pin cables. Since they’re not PWM, you can configure the fan curve in the motherboard BIOS. Connecting all three fans to one header with the splitter should allow you to control their speeds together.
I don't agree with your reasoning; PWM splitter cables function well and you don't need a hub. The fan speed is drawn from one of the split fans, and the PWM signal is sent to all of them. The motherboard can estimate fan speeds and manage them together. Noctua offers 2-way PWM splitters with each PWM fan they sell, allowing you to purchase higher ratio cables or connect them in series. Some models, such as the Arctic P12 PWM PST, include a built-in splitter in every cable, making it easy to link multiple fans. The P12 draws only 0.08A, so you can fit around 12 units on a single 1A header. Generally, fan hubs seem unnecessary unless you're working with very high-power fans.
Connecting the cooler's radiator fans to the CPU and CPU opt fan header, while leaving the pump cables unconnected, is generally safe. It won't damage your system as long as the connections are secure. To use your CPU, CPU opt, and pump headers on your Asus ROG Strix Z270 G Gaming motherboard, ensure all headers are properly matched and powered correctly.